Overview: Consuming an ounce of peanuts or adding a teaspoon of herbs and spices to your daily diet positively impacts the health of your gut bacteria and improves immune function.
Source: Penn state
Adding an ounce of peanuts or about a teaspoon of herbs and spices to your diet daily may affect the composition of gut bacteria, an indicator of overall health, according to new research from Penn State.
In two separate studies, food scientists studied the effects of small changes in the average American diet and found improvements in the gut microbiome.
The human gut microbiome is a collection of trillions of microorganisms that live in the intestinal tract. The bacteria there can affect almost all systems of the body, including metabolism and the building and maintenance of the immune system.
“Research has shown that people who have a lot of different microbes have better health and a better diet than people who don’t have a lot of bacterial diversity,” said Penny M. Kris-Etherton, Evan Pugh University Professor of Nutritional Sciences, Penn state.
For the peanut study, which was published in the journal Clinical nutritionKris-Etherton and her colleagues compared the effects of snacking on 28 grams (about 1 ounce) of peanuts per day, versus a higher carbohydrate snack — crackers and cheese.
After six weeks, participants who ate the peanut snack showed an increased abundance of Ruminococcaceae, a group of bacteria linked to healthy liver metabolism and immune function.
In the herb and spice study, published in The magazine for nutritionscientists analyzed the impact of adding blends of herbs and spices – such as cinnamon, ginger, cumin, turmeric, rosemary, oregano, basil and thyme – to the controlled diets of participants at risk for cardiovascular disease.
The team studied three doses — about 1/8 teaspoon per day, just over 3/4 teaspoon per day and about 1 1/2 teaspoon per day. After four weeks, participants showed an increase in gut bacteria diversity, including an increase in Ruminococcaceae, particularly with the medium and high doses of herbs and spices.
“It’s such a simple thing that people can do,” Kris-Etherton said. “The average American diet is far from ideal, so I think everyone could benefit from adding herbs and spices. It’s also a way to reduce sodium in your diet, but flavor food in a way that makes it appetizing and even delicious! Taste really is a top criterion for why people choose the food they eat.”
Both studies positively evaluated the increase in Ruminococcaceae and bacterial diversity as scientists learn more about the link between the gut microbiota and a spectrum of health factors, from blood pressure to weight. However, Kris-Etherton is quick to point out that more research is needed to understand all the implications.
She said, “We need a lot more research into the microbiome to see where it’s right in terms of overall health.”
Peanut Study: The work was supported by The Peanut Institute and Penn State’s Clinical & Translational Research Institute. This research was also supported by a grant to Juniata College from the Howard Hughes Medical Institute through the Precollege and Undergraduate Science Education Program, as well as the National Science Foundation.
Spice Study: This study was funded by the McCormick Science Institute. In addition, the study was supported by the National Center for Advancing Translational Sciences, NIH. The study also received computer resource support from the Howard Hughes Medical Institute through the Precollege and Undergraduate Science Education Program, as well as the National Science Foundation.
About this news about nutrition and microbiome research
Author: Sara LaJeunesse
Source: Penn state
Contact: Sara LaJeunesse–Penn State
Image: The image is in the public domain
Original research: Open access.
“Peanuts as a nighttime snack enrich butyrate-producing bacteria compared to a lower-fat, higher-carbohydrate isocaloric snack in adults with elevated fasting glucose: a randomized crossover study” by Philip A. Sapp et al. Clinical nutrition
“Herbs and spices modulate gut bacteria composition in adults at risk of CVD: results from a pre-specified exploratory analysis of a randomized, crossover, controlled diet trial” by Kristina S. Peterson et al. Nutrition magazine
Peanuts as a nighttime snack enrich butyrate-producing bacteria compared to a lower-fat, higher-carbohydrate isocaloric snack in adults with elevated fasting glucose: a randomized crossover study
Tree nuts have gluco-regulatory effects and influence the composition of the intestinal flora. The effect of peanuts on the microbiota has not been studied.
The aim was to investigate the effect of 28 g/d peanuts for 6 weeks, compared to an isocaloric snack with a lower fat, higher carbohydrate content (LFHC), on the composition of the intestinal flora. A secondary goal was to identify functional and active compositional differences in a subset of participants using metatranscriptomics.
In a randomized, crossover trial, 50 adults (48% female; 42 ± 15 years; BMI 28.3 ± 5.6 kg/m2; plasma glucose 100 ± 8 mg/dL) consumed 28 g/d dry roasted, unsalted peanuts (164 kcal; 11% E carbohydrate, 17% E protein, 73% E fat and 2.4 g fiber) or an LFHC snack (164 kcal; 53% E carbohydrate, 17% E protein, 33% E fat and 3 g fiber) for 6 weeks (4 week washout period). Gut bacteria composition was measured using 16S rRNA sequencing in the whole cohort. Exploratory metatranscriptomic analyzes were performed on a random subset (n = 24) of samples from the Peanut condition.
No differences between the conditions in α or β diversity were observed. After ingesting peanuts, Ruminococcaceae were significantly more numerous [Linear discriminant analysis score (LDA) = 2.8; P = 0.027)] compared to LFHC. Metatranscriptomics showed increased expression of the K03518 gene (aerobic carbon monoxide dehydrogenase small subunit) after peanut ingestion (LDA = 2.0; P = 0.004) and Roseburia intestinalis L1-82 was identified as a contributor to the increased expression.
Herbs and spices modulate gut bacterial composition in adults at risk of CVD: results of a pre-specified exploratory analysis of a randomized, crossover, controlled diet trial
Herbs and spices are rich in polyphenolic compounds that can influence the composition of the intestinal bacteria. The effect of culinary doses of herbs and spices consumed as part of a well-defined diet on the composition of gut bacteria has not been studied before.
The aim of this pre-specified exploratory analysis was to investigate the composition of the gut bacteria according to an average American diet (carbohydrates: 50% kcal; protein: 17%; total fat: 33%; saturated fat: 11%) with herbs and spices at 0.5, 3.3, and 6.6 gd–1.2100 calories–1 [low-, moderate-, and high-spice diets, respectively (LSD, MSD, and HSD)] in adults at risk of CVD.
Fifty-four adults (57% female; mean age ± SD: 45 ± 11 years; BMI: 29.8 ± 2.9 kg/m2; waist circumference: 102.8 ± 7.1 cm) were included in this 3-period, randomized, crossover, controlled diet study. Each diet was fed for 4 weeks with a minimum washout period of 2 weeks. At the beginning and end of each diet period, participants provided a fecal sample for 16S rRNA gene (V4 region) sequencing. QIIME2 was used for data filtration, sequence clustering, taxonomy assignment and statistical analysis.
α-diversity assessed by the observed trait metric ( P = 0.046) was significantly greater after the MSD compared to the LSD; no other dietary differences in α-diversity were detected. Differences in β diversity were not observed between the diets ( P = 0.45). Compared to baseline, β diversity differed across all diets ( P < .02). Enrichment of the Ruminococcaceae family was observed after the HSD compared to the MSD (relative abundance = 22.14%, linear discriminant analysis = 4.22, P = 0.03) and the LSD (relative abundance = 24.90%, linear discriminant analysis = 4.47, P = 0.004).
The addition of herbs and spices to an average American diet caused shifts in gut bacteria composition after 4 weeks in adults at risk of CVD. The metabolic implications of these changes deserve further investigation. This trial is registered on clinicaltrials.gov as NCT03064932.